The more I think about it, the more I'm realizing this is the easiest way to discontinue the Xbox brand of consoles altogether and merge it into their Windows platforms.
Had MS released Xbox Two or whatever, and it sold less than estimated, then that damages the brand even more. Hardware refreshes like this will allow MS to refer to the "Xbox Family" and MAUs much easier. There won't need to be major R&D costs for a new piece of hardware because they just have to keep updating components incrementally. It'll allow the Xbox to suffer whatever fate it has infront of it in a way that will be somewhat invisible to the general public, keep hardcore Xbox fans interested (or have them bail out onto the Windows 10 platform where they can play all their XB exclusive games), and so on.
This is a terrible idea from a mass market perspective but that's not what they're aiming for. They're folding Xbox into Windows, and this is kind of a brilliant move in doing it slowly but steady without causing a large amount of waves. It won't sell anything what a Playstation 5 might sell, but that's the point, because by then MS would want to be out of the console game and selling PC boxes at that point, some with the Xbox branding on it.
I always knew XB1 would be Microsoft's last console but the way they're transitioning is kind of brilliant. Well, maybe not from a sales point of view, but in keeping their Xbox brand healthy while trying to attract a new gaming audience for Windows 10? Absolutely.